Condensed Consolidated Balance Sheets (Parenthetical) $ in Thousands	Sep. 30, 2018 USD ($) shares	Dec. 31, 2017 USD ($) shares
Statement Of Financial Position [Abstract]
Accounts receivable, related party amount, current | $	$ 457	$ 821
Prepaid expenses and other current assets, related party amount | $	52	1,871
Accrued expenses related party amount, current | $	234	0
Deferred revenue non-current related party amount | $	$ 0	$ 91
Common stock, shares authorized	51,893,132	41,092,969
Common stock, shares issued	51,862,415	41,037,121
Common stock, shares outstanding	51,554,479	40,592,248
Common stock, conditional capital	19,520,914	16,419,632
Treasury stock, shares	307,936	444,873